so in the end you're using a sub directory?
it sounds like you're using something like mod-rewrite in Apache (i've never worked with IIS)
did you tell the vbulletin team that you're using IIS? i'm admin of a forum that uses the same vb version as TF does and the vb support teams support has been pretty thorough
is it possible that you're not familiar enough with the installation environment and maybe that made it seem like their support was bad?
well, in any case, i'm glad you sorted it out.